40sw Keyholing

[Hometek]

First the particulers. Walther p99 40sw, Lee 2-Cavity Bullet Mold TL401-175-SWC, WW lead, alox tumble lube, 4 gr reddot powder.

This the first casting for handgun boolits I've done. Been a long learning curve for me. Had FTF's at first. Solved that with seperate Lee crimper die. Took 100rds today to test on paper and had 4 out 12 keyhole. Accuracy was fair. Similar to WWB. What's interesting is that several of the xring hits were keyholes.

When I got home I decided to measure the boolits. Barrel slugs at .400 the best I can tell. Had trouble getting a good slug so I'm looking for some pure lead to try again. Boolits are measuring .404 to .405. I've ordered a lee sizing die kit to fix that.

I did asearch on here on keyholing and all the posts I read suggested it was undersized boolits that keyhole. Has anyone experienced keyholing with oversized boolits? Would the reddot powder be the culprit having a faster burn rate? I haven't been able to get my new chrony working consistently but when it appeared to be getting accurate readings (when known ammo fired read correctly) it was in the 950fps range.

[462]

Hometek,
Keyholing is a symptom of a too small boolit. I suspect that the Lee Factory Crimp Die may be the culprit, downsizing your boolits to jacketed diameter. Load some more rounds without using the FCD and see what happens.

[Trey45]

I suspect the same thing 462 suspects. Here's what you do. Take a measurement of the bullet, load it as you're doing now, pull the bullet and measure it again, if it's been sized down your culprit is the crimp die. I noticed where you said you were having FTF prior to using the FCD, were you getting keyholes then as well, or did they begin when you began using the FCD?

[Hometek]

It's not a factory crimp die its a Lee Taper Crimp Die. I'm seating the bullet with the seater die turned back so it doesn't crimp. The taper die is set for a light crimp. The bullet pulled from the case is still original size.


I suspect the same thing 462 suspects. Here's what you do. Take a measurement of the bullet, load it as you're doing now, pull the bullet and measure it again, if it's been sized down your culprit is the crimp die. I noticed where you said you were having FTF prior to using the FCD, were you getting keyholes then as well, or did they begin when you began using the FCD?


I'm not sure if it was key holing. I never shot it on paper. What was happening before was that the bullet was shaving lead when I was seating/crimping at the same time leaving a ring that would prevent the cartridge to chamber all the way.

I guess I'll have to wait for the sizer and see what it does.

[mooman76]

I agree with the others. Try backing off on the crimp or use another crimp die.

[Hometek]

If the pulled bullet is the same size as before loaded how is the crimp affecting it? .405 before .405 after.

[Hometek]

I'm going to pull 10 boolits and see what I get. My experience with casting boolits is like the Bible story about Naaman being to told to dip 3 times in muddy Jordan. Even when it don't make sense I might of well try it.

[243winxb]

Wait till you get a sizer. Your bullets are just to big to load with out shaving lead. Edit-Make sure its not the target backer making the holes look that way.

[243winxb]

4 gr reddot powder. Could this be to light?:confused: Maybe try 4.5gr of Red Dot?:confused: I don't see much data for it with lead bullets.:smile: